Chemical coating compound for protecting glassy surfaces exposed to the external environment

ABSTRACT

A Coating chemical compound for protecting glassy surfaces exposed to the external environment comprising silicon dioxide, in percentage between about 0.3÷2% approximately, isopropyl alcohol (2-propanol) in percentage between 60÷70% approximately, 1-methoxy-2-propanol in percentage between 15÷25% approximately, ethanol in percentage between 0.5-3.5% approximately and ethyl silicate in percentage between 0.1÷1% approximately.

The present invention fits in the field of the protection nanotechnologies and concerns a chemical coating compound for protecting glassy surfaces exposed to the external environment.

The present invention also concerns the use of such a chemical coating compound for the formation of a transparent and invisible film (or patina), suitable for protecting glassy surfaces exposed to the external environment, for instance windows of buildings, solar panels, photovoltaic panels and wind paddles just to quote the main applicative fields, with which the transparent film is firmly coupled.

Document published with N. WO2009/074570 relates to a method for creating a break-resistant coating of paint of alkyl silicate by applying one of the compositions presented and described therein to a purely metallic surface.

Document published with N. WO2006/049935 refers, on the other hand, to a self-binding coating composition for the production of solid cores of electrical steel sheets to be used in electrical equipment.

Finally, document published with N. JP2006098444 concerns an antireflection and scratch-resistant laminate sheet, obtained by applying, in the order, a scratch-resistant layer and an antireflection layer to the surface of a transparent substrate.

As known, moreover, in the field of the chemical products a silicon-based chemical compound has been recently developed and obtained, which can be advantageously used for covering and consequently protecting glassy surfaces such as typically the glass of cars.

The chemical coating compound in question is object of European patent application published as EP 1634933. Such a chemical coating compound, when uniformly smeared on the glass of the car, forms a transparent, invisible and very thin film that, by virtue of its chemical formulation, favours disposal and slipping of gnats, birds casts, impurities or dust of any nature or kind, thereby preventing them from firmly and lastingly sticking to the glass which is thus kept clean.

The aforesaid transparent film reveals undoubtedly extremely effective for the function just described, when coupled with the glassy surface installed on the car body.

However, fro such a chemical coating compound or transparent film formed thereof some recognized drawbacks still persist, mainly related to the long time required for the chemical coating compound, once lying on the outer face of the glassy surface, to dry and harden in order to become the transparent film. Another drawback of the chemical coating compound of the prior art here considered is due to the fact that drying and hardening of such a compound, when applied to the glassy base surface, must be necessarily performed in an industrial oven of drying.

This leads to an inevitable and, though limited, still unwanted power consumption, directly proportional to the set speed of drying.

The present invention seeks to overcome the drawbacks of the current state of the art just mentioned.

More specifically, primary purpose of the present invention is to provide a chemical coating compound which, when applied to cover the face of the glassy surface exposed to the external environment, presents a time of drying and hardening almost immediate and in any case shorter than equivalent chemical compounds of known type.

It is a second purpose of the invention to devise a chemical coating compound of glassy surfaces exposed to the external environment which solidifies quickly and, in addition, in a nearly spontaneous way or, anyway, without the need to be introduced in a industrial oven of drying, as instead envisaged for similar compounds nowadays commercially available.

Within such a purpose, it is task of the invention to reduce compared to the known art energy consumption to be incurred in order to effectively apply a transparent coating film to a generic glassy surface making it repellent to any kind of impurity that comes in contact with it.

It is another task of the present invention to simplify in respect of the prior art the activities that the manufacturer must implement in order to make a glassy surface, whose face to be exposed to the external environment is coated with a transparent protective film, definitely and really repellent to any kind of impurity that comes into contact with it.

Said purposes are achieved through a chemical coating compound for protecting glassy surfaces exposed to the external environment as the attached claim 1, as hereinafter explained for the sake of brevity.

Object of the present invention is the use of said chemical coating compound as transparent protective film smeared on glassy surfaces exposed to the external environment, such as windows of buildings, solar panels, photovoltaic panels and wind paddles, according to the appended claim 11, as hereinafter referred for the sake of exhibition simplicity too.

Advantageously, thanks to its particular formulation, the chemical coating compound object of the invention, once applied to uniformly cover the face of the glassy surface exposed to the external environment, dries and hardens almost instantly and in any case more rapidly than known similar chemical compounds.

Still advantageously, the chemical coating compound of the invention applied to the glassy base surface forms a transparent film that completely solidifies in the said short times but in an almost spontaneous manner, without requiring that the formed assembly must be introduced together into an industrial oven of drying. Equally advantageously, this allows to limit compared to the known technique the energy consumptions to be sustained in order to effectively apply to a generic glassy surface a transparent film that is produced by the effect of drying of the chemical coating compound on the glassy surface itself in order to make the latter repellent to any kind of impurity (gnats, birds casts, dusts and so on).

Furthermore, in advantageous manner, the invention makes easier than the state of the art the operations to be implemented in order to effectively make a glassy surface repellent to any kind of impurity that comes into contact with it in the just mentioned way.

Further features and peculiarities of the invention will appear to a greater extent from the description that follows, related to an illustrative and preferred, but not limited to, embodiment of the chemical coating compound, here exclusively claimed, suitable for protecting glassy surfaces exposed to the external environment.

Such a chemical coating compound comprises silicon dioxide (or silica, SiO₂ as raw or molecular formula) in percentage between about 0.3÷2% and generally in the amorphous state.

In accordance with the invention, the chemical compound also includes the following chemical components:

-   -   isopropyl alcohol (2-propanol, C₃H₈O as raw or molecular         formula, structural isomer of the propanol) in percentage         between about 60÷70%;     -   1-methoxy-2-propanol (C₄H₁₀O₂ as raw or molecular formula) in         percentage between about 15-25%;     -   ethanol (C₂H₅OH as raw or molecular formula) in percentage         between 0.5÷3.5%;     -   ethyl silicate (Si(OC₂H₅)₄ as raw or molecular formula) in         percentage between 0.1÷1%.

Preferably, the percentage of ethyl silicate Si(OC₂H₅)₄ is 0.4%.

The chemical coating compound described herewith also presents the following physicochemical properties:

-   -   open tank flash point equal to 15.5° C.;     -   melting point equal to −90° C.;     -   boiling point equal to 82.5° C.;     -   evaporation ratio (understood as ratio between the evaporation         temperature of a given material and that one of a specific         reference material) equal to 2.88;     -   specific density (or relative, understood as ratio between the         density of a given substance and that one of a specific         reference substance) equal to 0.8 at room temperature;     -   vapour pressure (air=1) equal to 4.4 KPa at a temperature of 20°         C.;     -   relative vapour density equal to 2.1 at a temperature of 15° C.

In particular, the ratio of evaporation is useful for assessing the health risks and fire danger of a material.

The chemical coating compound object of the present invention is substantially colorless and transparent and presents an odour of mild characteristic alcohol. Furthermore, such a chemical compound presents a viscosity between about 50-100 KU (KREBS Unit) at a temperature of 20° C., measured according to the ASTM D562 method through viscometers of Stromer's type.

The subject of the present invention is also the use of the chemical coating compound previously described as transparent protective film, smeared on glassy surfaces exposed to the external environment, such as windows of buildings, solar panels, photovoltaic panels and wind paddles.

More specifically, the transparent protective film is formed by drying and hardening the chemical coating compound itself previously kept at the liquid state. From such a state, the chemical compound is applied:

-   -   on existing surfaces, already installed, through spray guns with         nozzle 1.0/1.2, dehumidifier in air line with manometer in order         to standardize the air pressure to 5 atmospheres at calcium;     -   in line, directly during the manufacturing process of the glassy         surfaces to be positioned, with industrial spray system, at any         time before packaging.

The chemical coating compound in question, when at the liquid state, presents a very fast drying time—equal to 120 minutes at 10° C., 60 minutes at 20° C. and 30 minutes at 30° C.—which makes the chemical compound itself extremely advantageous and effective compared to equivalent compounds of known type.

Indeed, the chemical compound of the invention, thanks to its special formulation, aggregates and reticulates immediately and automatically, just smeared, to the quartz which typically constitutes the glassy surface to which is applied, clogging up the pores thereof.

The piece made from the simple aggregation of the aforesaid transparent film to the pre-existing glassy surface, is yet a finished product, ready to be mounted, after a reduced time interval and not a semi-finished product which, in order to reach the final configuration in proper times, must be introduced into a drying oven, as it happens in the equivalent known art.

Such an objective is achieved without in any way affect the capacity of the transparent film to prevent any kind of impurity, such as dust of various kinds, gnats, birds casts and so on, to remain attached to it.

The transparent film obtained from drying and hardening of the chemical coating compound of the invention is also resistant to UV-A and UV-B ultraviolet radiations, in particular with respect to the UV-A radiations it contributes to the shielding of the range between 280 and 400 nm (nanometers), therefore resulting, beyond to unreliable to ozone and sunlight, even an effective protection for the yellowing and opacification processes of the glassy surface.

Preferably but not necessarily, the transparent film presents a thickness of 0.8 μm (micrometers).

The application of the chemical coating compound on glassy surfaces exposed to the external environment, such as windows of buildings, solar panels, photovoltaic panels and wind paddles, allows to get a finished product with a guarantee of 10 years.

The chemical coating compound of the invention is used with the purpose to keep clean the glassy surfaces, avoiding the adhesion of substances that dirties these glassy surfaces.

This thanks to the filling of the interstices present in the glassy surface to be treated at nanometric level. Indeed, by closing these interstices the soiling extraneous elements, such as dust, sand, atmospheric particles, pollen and even more, fail to adhere in stable manner and, consequently, they don't remain settled therein.

Even if the soiling elements however succeeded in settling, the simple action of atmospheric agents such as wind or rain would be able to effectively remove them.

In addition and at the same time, the chemical coating compound here claimed involves greater transparency (or reduction of the surface reflection) in case of building applications (windows, lamps and so on), and a higher transmittance in case of applications in solar photovoltaic circle, in thermal direct field or by means of mirrors.

The chemical coating compound of the invention allows indeed to limit the amount of light reflected by the glassy surface, thus determining a full use of the incident beam.

As a result positive effects arise which can be really found and measured, such as in the photovoltaic field, where the power of the module is normally increased by the compound of the invention from a minimum of 1% to a maximum of 2.5%.

At the light of the foregoing, the chemical coating compound of the invention, when in use at the solid state, forms a transparent film on the glassy surface to which is applied ensuring the maintenance of high cleanliness levels for longer times and consequently an increase in the transmittance due to the molecular set up of the silicon which, after all, reflect in:

-   -   recovery of cash flow as a result of not incurred costs         approximately equal to 60%;     -   significant energy saving due to the constant maintenance of the         performances.

On the basis of the foregoing, it is, therefore, understood that the chemical coating compound for protecting glassy surfaces exposed to the external environment, object of the present invention, achieves the purpose and reaches the advantages mentioned above. It is, then, clear that many other variations can be made to the chemical coating compound in question, without departing from the principle of novelty intrinsic in the inventive idea expressed here, as it is clear that, in the practical implementation of the invention, materials can be changed, as needed, and replaced with others technically equivalent. 

1. Coating chemical compound for protecting glassy surfaces exposed to the external environment comprising silicon dioxide, in percentage between about 0.3-2% approximately, characterized in that it includes the following chemical components: isopropyl alcohol (2-propanol) in percentage between 60÷70% approximately; 1-methoxy-2-propanol in percentage between 15÷25% approximately; ethanol in percentage between 0.5-3.5% approximately; ethyl silicate in percentage between 0.1÷1% approximately.
 2. Chemical compound as claim 1) characterized in that it presents a flash point in open vessel equal to 15.5° C.
 3. Chemical compound as in claim 1) characterized in that it presents a melting point equal to −90° C.
 4. Chemical compound as defined in claim 1 characterized in that it presents a boiling point equal to 82.5° C.
 5. Chemical compound as defined in claim 1 characterized in that it presents an evaporation ratio equal to 2.88.
 6. Chemical compound as defined in claim 1 characterized in that it presents a specific (or relative) gravity equal to 0.8 at room temperature.
 7. Chemical compound as defined in claim 1 characterized in that it presents a vapour pressure equal to 4.4 KPa at a temperature of 20° C. and a vapour density equal to 2.1 at a temperature of 15° C.
 8. Chemical compound as defined in claim 1 characterized in that it presents a mild characteristic alcohol odour.
 9. Chemical compound as defined in claim 1 characterized in that it presents a viscosity of between 50-100 KU (KREBS Unit) approximately at a temperature of 20° C., measured by the ASTM D562 method by means of viscometers of Stromer's type.
 10. Chemical compound as defined in claim 1 characterized in that it presents a drying time of 120 minutes at 10° C., 60 minutes at 20° C. and 30 minutes at 30° C.
 11. Use of the coating chemical compound according to claim 1) as a protective transparent film smeared on glassy surfaces exposed to the external environment such as windows of buildings, solar panels, photovoltaic panels and wind vanes.
 12. Use as claim 11) characterized in that said transparent film has a thickness equal to 0.8 μm (micrometers).
 13. Use as claim 11) characterized in that said transparent film is resistant to ultraviolet UV-A and UV-B radiations resulting proof to ozone and sunlight and effective protection for the processes of yellowing and opacification of said glassy surface. 